Peruvian fishermen illegally kill up to 3,000 dolphins a year, conservation group Mundo Azul states. The dolphins are used for human consumption and as bait for sharks.

The demand for shark fins, especially in China, fuels a lucrative international market for shark hunting. Peruvians consume most of the shark meat nationally, and export the fins. Other countries also use dolphins as bait for sharks. Additionally, overfishing has driven people in poorer countries to increasingly turn to dolphins and marine mammals for food.

The Peruvian government issued a ban on dolphin hunting in 1996, but has not successfully enforced it. Due to the video – taken by investigative journalists with the support of Mundo Azul and ocean conservation organization BlueVoice.org – the Peruvian government says it will take further action to prevent dolphin hunting.

A national conservation plan is scheduled to launch in mid-2014, Peru’s deputy minister for fishing announced. The government will also consider banning shark hunting.

Removing top predators, such as sharks and dolphins, from ecosystems can have profound effects on the environment.

“The removal of apex predators entails that the population rates of their prey species are not kept in check,” a report by the independent research group Council on Hemispheric Affairs states. “These prey species can then reproduce without control and can throw an ecosystem out of balance.”

Sharks and dolphins also reproduce slowly, which makes them especially vulnerable to population declines. Furthermore, eating dolphins can result in negative health effects, including mercury poisoning.

“It was a lot more common than we expected,” Martin Robards, an author of the study, said in a blog post for the scientific journal Nature.

Peru’s anchovy-filled seas are the world’s primary source for fish meal, which plumps up farmed seafood and agricultural livestock. The tiny fish also feed larger ocean animals, drawing them to Peru’s coast.

Due to overfishing, the number of anchovy in Peru’s seas continues to plummet, which results in soaring seafood prices.

“With so much overfishing, particularly of anchoveta, fresh fish of all sizes are now scarcer than ever for Peruvians, and seafood prices have risen since 2009 at a rate four times that of other foods,” an Associated Press article reports.

A sea captain filmed in the undercover video cites high seafood prices as one of the reasons he uses dolphins as bait.

“‘I understand that to hunt the dolphin is illegal. But for me, it’s a necessity, [sic] I do it to keep my bills down. I can minimize my costs, because the bait for shark is very expensive,” he said.

Government mandates can drive dolphin hunts underground, Robards told Nature. He recommends working with local populations to find alternative food sources.

Rather than hunting dolphins, Peruvian communities can use dolphin and whale watching tours as an alternative source of income, Mundo Azul says.

Conservationists also hope the steadily decreasing demand for shark fins in China will further discourage dolphin and shark hunts.